Counterfeiting and forgery have become significant concerns in the modern economy and marketplace. Advances in computing technology and printing techniques have increased the incidence of forgeries, counterfeited documents, and other fraudulent activities. Countless areas of today's high-technology society require and rely upon certification, authentication and protection of highly valuable documents, papers, currency and other materials. Thus, there is a need for security markings to be incorporated into currency, important documents, packaging, and other authentic materials to prevent unauthorized copying, forging, counterfeiting and other fraudulent use.
While fraudulent activities such as counterfeiting currency and forging signatures or handwriting are common, methods of creating and perfecting forgeries and counterfeit documents have become easier and more available with the advent of highly sophisticated computer printing and processing. As far back as 1991, the United States Treasury has continually added security safeguard features to the denominations of currency in an attempt to combat the use of counterfeit money. These safeguards have included watermarks, security threads embedded in the paper, microprinting, color-shifting ink, and the use of multi-colored bills.
Current methods of authentication of currency involve visual observation, scanning under ultraviolet lamps, notes containing security threads, and emissive materials such as inks and planchettes. Such security threads emit a distinct marking, color or code in response to exposure to the ultraviolet light. In some circumstances, the emissive features of different denominations of notes can emit different colors. In addition to the colors of the emission, a code number or other unique identifier can be detected by the naked eye when the note is exposed to ultraviolet light or excitation of some form.
Authentication of security articles, such as valuable documents or materials, affects many facets of the economy. Notary publics use a raised stamp to authenticate notarized documents. In turn, drivers' licenses, passports and other photographic identification contain holograms and microprinting. Similarly, sporting memorabilia and retail clothiers use holographic tags and stamps to prove authenticity. Even fashion designers are now including authentication devices in their clothing to prevent passing off of knock-offs as designer products.
For example, if a counterfeiter is aware there is a security thread in a bill or a watermark in a document, then replication of the security feature will be easier. Once a feature is made known, a counterfeiter may begin to develop specific strategies and solutions to overcome the security protections provided by the specific feature.
Accordingly, a need exists for security features that further reduce a counterfeiter's likelihood of success, even if they are aware of the existence of the security feature.